You may have winced at that squirrel catapult we showed you a couple of months ago, but here's a Rube Goldbergesque contraption that squirrels willingly navigate. Look at those little guys running the obstacle course, willing to do just about anything for their next meal. One of the ambitious rodents ran the course 20 times in one day! Don't miss the end of the video for another example of a unique squirrel/machine interface. [Vooba]